Production of metal colloids.



" r ens Ara FIQ.

HENRY OROOKES AND LEWIS STROUD, OF LONDON, ENGLAND.

nuc'rron or METAL cottoms'.

1 1 16,241; No Drawing.

Specification of Letters Patent.

Application filed December 8, 1913. Serial No. 805,444.

Patented Nov. 3, 11914,.

To all whom it may concern:

Be it known that we, HENRY GRooKEs and LEWIS STRoUD, residing in London, England, have invented certain new and useful Improvements in the Production of Metal Colloids, of which the following is a speci-- fication.

In producing metal colloids from a dilute mixture obtained in a known manner by dissolving some organic body such as pep- .tone in distilled water with an addition of common salt and cooling the mixture after boiling for the purpose of proper dissolution according to the specification of our Letters Patent No. 1059841, it has already been proposed to add tothe mixture a very dilute solution of salts of metals.

We have .noivfound that in some cases metallic colloids "having a very marked Brownian movement visible under the ultra-microscope, maybe obtained solely by a reducing action between the peptone and the salt of metal used in the process. The condition, however, in having the metal salt employed in a very dilute solution of about the order of 1 part of metal in 1000 of solution -is also essential in the present process. In

this process, however, we dispense with the use of common salt, "For example, according to this invention wefproduce silver colloid by adding a dilute solution of silver nitrate to a solution of peptone of the strength and proportions set out inthe specificati on of the Letters Patent above referred to, and to the mixture we add about 0.1% phenol, it being essential during the mixing, of the two solutions to pour the solution of the silver salt into the solution of peptone and not vice versa.

In order to produce iron colloid according to this invention, we take a very dilute solution of perchlorid of iron, about the same order of 1 in 1000 and add this solution to a solution of peptone (about 150 grains in one quart of water), a small percentage of phenol (0.1%) being again added to the mixture. v l

The addition of phenol to metal colloids has the object to render the mixture permanently stable, experience having shown that some metal colloids under certain conditions not 'yet fully understood have the tendency to break down after a certain period and We have found that if a small percentage of' phenol is added such tendencies are counteracted and the colloidal solution is rendered substantially permanent.

It is noted that'while we have claimed nitrate of silver we regard as e uivalents protonitrate of mercury. and perc lorid of Iron.

What We claim and desire to secure by .Letters Patent is: 

